Smaller homes use less material. Design space efficiently
for what you really need to live in. Consider whether you
really need; three living spaces and three bathrooms, or perhaps
one of each would do? Compare the housing we expect in the
wealthy developed world to that which the majority of the
planet’s population live in due to poverty and lack
of opportunity. Imagine if everyone in the world expected
to use resources in the same way that we do to build a home.
Where ever possible select materials that are harvested, produced
and manufactured as close to the building site as possible.
The heavier that a product is and further it travels, the
more transport energy is used and greenhouse gas produced.
The energy used to harvest, extract, manufacture, transport
and install products is called the material’s “embodied
energy”. Mud bricks have a very low embodied energy
as does recycled timber whereas new aluminium has a very high
embodied energy per cubic metre. Sometimes a higher embodied
energy material may be appropriate to use in the right way,
for example a concrete slab on ground. Also while structural
steel has a higher embodied energy than timber per cubic metre,
a highly efficient light weight hollow steel section may do
the same job as a heavy timber post many times its weight.
Selecting local materials gives you a chance to visit the
source of the product and assess how responsibly the resources
are harvested. It is more responsible to harvest our own resources
and make good any damage than to shift that burden elsewhere.
Toxicity during manufacture of materials or during the life
of a building is an important consideration. Always use physical
termite barriers over chemical ones, consider using poly pipes
in lieu of UPVC, and consider using other products than those
with urea formaldehyde glues.
Llewellyn Pritchard, Director
of Conscious Homes is an ESD consultant, registered Architect,
a registered Builder (Domestic Unlimited and Commercial Unlimited),
an HIA Greensmart Builder and writer. Conscious Homes won the 2006
National
HIA Greensmart Resource Efficiency Housing Award.
